Road-cart



(No Model.) 2 sheetssheet 1 s. B. IRWIN.

ROAD CART.

'No. 449,121 Patented Mar. 31', 1891.

. flyentor (No Model.) 2 Sheets-Sheet 2.. S. B. IRWIN.

. ROAD OART. No. 449,121. Patented Mar. 31,1891.

' ja adv? MM @W MK 1 5 "cam Finns-0a., mwnrumm, wunmn'ron n c UNTTEDSTATES PATENT @FFICE.

SAMUEL B. IRWIN, OF \VES" HEBRON, NElV YORK.

ROAD-CART.

SPECIFICATION forming part of Letters Patent No. 449,121, dated March31, 1891.

Application filed July 24, 1890. $erial No. 359,820. (No model.) A

To all whom it may concern.-

Be it known that I, SAMUEL B. IRWIN, a citizen of the United States,residing at West Hebron, in the countyof Washington and State of NewYork, have invented certain new and useful Improvements in Road-Carts;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to an improvement in road-carts, the objectthereof being to simplify, perfect, and greatly improve the constructionof carts or vehicles of this kind; and the invention consists in theconstruction, arrangement, and combination of parts, substantially aswill be hereinafter described and claimed.

In the accompanying drawings, illustrating my invention, Figure 1 is asectional side elevation on the line so a; of Fig. 2. Fig. 2 is a topplan View of my improved road-cart. Fig. 3 is a detailed side viewshowingcertain features of construction. Fig. 4 is an enlarged view ofthe clip which holds the spring beneath the cross-bar, said spring andcross bar being shown in section. Fig. 5 is an enlarged detail view ofone of the devices that are attached to the vehicle-frame and connectedto the inner ends of the springs. Fig. 6 is an enlarged section on theline y y of Fig. 1. Fig; 7 isa detail plan and edge view of one of theplates that are used with the elliptical springs.

Like letters of reference designate corresponding parts throughout allthe different figures of the drawings.

B B denote the wheels, B the axle, O the seat, D the forward portion ofthe body or foot rest, and b Z; the thills or shafts, of a twowheeledvehicle or road-cart, and c the crossbar connecting these thills, and (Zthe whiffletree pivoted on the cross-bar, these parts being shown herefor the purpose of illustration, in order to indicate how myimprovements are applied thereto and operatively arranged in connectiontherewith for the purpose of perfecting, completing, bettering, andmaking more efficient the entire structure of the ve hicle.

Of course my improvements are applicable to road-carts of many andvarious kinds, and the special form of cart which is shown here is givenby way of example merely.

A A designate two spiral springs located alongside of the thills b 1)between the same and underthe cross-bar 0 near the ends thereof.

This is the preferable position of these springs,

although this exact location may be changed, if desired. The springs A Aare simple spirals having their ends preferably somewhat conical or ofless diameter than the central portions of the springs, and the extremeends of the wire which forms the springs are provided with loops oreyelets a a of a suitable size to admit of the passage therethrough of asuitably-sized bolt. The front end loops a a of the two springs areconnected by bolts to the small angle-irons G G, which are fastened tothe under sides of the thills b I), respectively, as shown, saidangle-irons being preferably slotted for the passage through them offastening-screws, by means of which said irons are secured to thethills. The slots permit the adjustment of said irons. These springs areheld up against the under side of the cross-bar c by means of clips 6.This arrangement is shown in the enlarged view of Fig. 4. The ends ofthe clip pass up through the bar a and are secured by nuts on the top ofthe bar. act easily, these clips 6 0 should loosely encir cle thesprings, each of which lies in its respective clip as on a bed, the clipserving simply to support the spring, but not bindingitorhinderingitsaction If the spring yields too easily, it is obviousthat the clip can be tightened by adjusting the nuts on the ends of theclip, and thus throwing the springs firmly against the cross-bar andlessening its flexibility of action. By increasing or diminishing thelength of that portion of the spring lying on the side of the clip nextto the cartbody, and to which the front end of the cartbody is attached,any desired degree of flexibility of the spring maybe attained, and thisadjustment can be very easily made by moving the aforesaid iron G, towhich the front end of the spring is connected, the movement beingeither backward or forward beneath the thill. If only a small portion ofthe coil is allowed to reach beyond the clip--that is, in frontthereof-the spring will be compara- In order that the springs may tivelystiff, while it a larger portion lies on that side the spring will beproportionately limber. The front end D of the vehicleframe is connectedto these springs by irons F F, which are shown very clearly in thedetail view in Fig. 5. These irons are angle: irons of suitable form,and they are secured to the sides of the body 13. The outer ends of theirons are fastened to the springs A A by means of bolts ff, which passthrough perforations in the irons and through the rear eyes a. All thisis clearly shown in Fig. This connection provides a pivotal joint, sothat the parts may move easily with relation to each other. Thus it willbe seen that the forward end of the cart-body is pivotally con nected tosprings which are supported beneath the cross-bar and whose forward endsare connected to irons on the thill. ward end of the cart-body hastherefore a yielding support.

It may be here remarked that a coiled or spiral spring has a doubleaction-that is, it has one action by which it yields to a straight ordirect pull, and this action maybe termed its direct action, and it hasanother action by which it bends upon itself, and this action may betermed its lateral action. It is the lateral action which mainly comesinto play when the spring is used in the manner that I use it inconnection with the front end of the road-cart, although the lateral andthe direct actions of the supporting-springs are combined in aconstantly-varying degree, according to the amount of strain.

\Vhen a cart or similar vehicle is properly balanced,the center ofgravity will fall sufficiently far behind the axle to aliowthe thills tobe carried at the level which they occupy when in the shaft-tugs. Theaxle is the center upon which the body turns when said body is securedin place by means of clips and springs, as in the case in the example ofvehicle we are now considering. Now if we suppose that the center ofgravity is behind the axle, the back part of the body, in movingbackward and downward, will describe an arc of a circle of which theaxle is the center, and at the same time the front end of the body willmove upward and backward, describing an arc of a greater circle of whichthe axle is also the center. From this it will be evident that while thefirst action in the coil is mainly lateral the direct action comes moreand more into play as the traction is increased. The flexibility of thecoil readily admits of this action, which may be said to take place in avarying oblique manner. The advantage of the coiled springs consists inthe fact that when they are used in this way a short and very effectivespring device is obtained, and one that readily adapts itself to theever-varying movement of the front end of the body, which movement, ashas been already exu plained, is constantly taking place in an arc of acircle of which the cart-axle is the center. The point aimed at in theconstruction of ve- The forhiclcs of this kind is to secure an extremelysensitive and yielding spring, so that the law of inertia may be availedof in the construction of a road-cart, so as to limit to the least;possible degree the unpleasant horse motion, as it is called, which isconstantly tak ing place during the progress of the cart. Obviously iftwo bodies have a solid connection between them one cannot be movedwithout a corresponding movement of the other; but if they are connectedby a yielding and extremely sensitive spring one of the parts,particularly if it be lighter in weight than the other, may be movedthrough a limited space without moving the other at all. Therefore thebody of a cart with one or more persons therein may be considered to bethe heavy body and the thills as the lighter body, the cart and thillsbeing united by a very flexi ble coil. These thills are secured to theaxle by a common buggy shackle, so that any horse motion that iscommunicated to the body must take place through the coils alreadydescribed. \Vhen the horse stops, the thills descend or drop to acertain extent. If the body is united or joined to the thills orcross-bar by a solid or a pivotal joint, it must of necessity movecorrespondiu gly. The front end of the body must move downward andforward, and the seat moving in the part of a circle of which the axleis the center will move almost directly forward. When the horse startsor goes forward, the movements are reversed, for the thills rise, thefront end of the body of the cart moving upward and slightly backward inthe are of a circle already mentioned, and the seat moves almostdirectly backward. This back and forth movement constitutes what isreferred to in speaking of the unpleasant horse motion. \Vhen the bodyand the thills are connected by means of an extremely sensitive oryielding coil, it will be seen that when the horse steps the thillsdescends as before and the strain of moving the body comes upon theyielding spring, which yields to the strain. If the lowered position ofthe thills should be kept up for any length of time, the springs byvirtue of their elasticity would draw the body forward and downward andthe former relation of the body and thills would be restored; but beforethe elastic action of the springs has time to come into play the horsewill move forward, thus rising and taking another step, and the thillsare raised above the mean level, and any movement of the body isarrested or prevented. Of course every succeeding step and the movementsaccompanying it are but a repetition of what I have just described. Itmay be estimated that a horse moving at a moderate rate when trottingtakes one hundred and fifty steps per minute. The thills make of coursethe same number of movements, but only through a very limited space, andas their connection with the body is by a very yielding spring thespring yields and the movements are so rapid that theyare lost in thespring and not communicated to the body. Thus united the thills move toofast for the body, and by taking advantage of the law of inertia the unpleasant horse motion is gotten rid of.

The location of the spring, as I have already once intimatedhereinabove, may be changed. They maybe placed under the thill under thecross-bar, in which case they reach from the [O thills toward the body,or they may reach from the thills alone toward the body; but in any ofthese positions the action is the same. The form of coil may also varyand the attachments at each end thereof may he changed without departingfrom the invention.

lVhenever the front end of the body of a cart is connected to thecross-bar or thills by means of any kind of springs, there is a tendencyin the cart-body to move or lurch 2o slightly forward just at the timewhen the movement of descent on the supportingsprings is completed. Thismovement is very similar initsresults to thehorse motion whichI haveabove described as being com municated z 5 to the cart-body from thethills. In order to effectually overcome this trouble, I provide strapsg g. These straps connect to the front end of the cart-body D, near eachside thereof, and also to the cross-bare. The straps buckle 3 at themiddle, so that their length maybe adjusted as maybe desired. The strapsshould be loose enough, so that they will not interfere with the descentof the body upon the springs, but not long enough to allow of motionbeyond this. Thus these straps prevent or arrest the lurching motion.Experience will dictate as to the adjustment of the length of thestraps. If they are too tight, the result will be to communicate thethill motion to the 4 body, and if too loose they will permit of theunpleasant lurching motion.

hen the body of a cart or similar vehicle is supported by means of apair of elliptical springs placed crosswise upon the axle, if the seatis placed evenly upon the springs the center of gravity will fall infront of the axle and too great weight will fall upon the back of thehorse. To obviate this trouble, the spring-bars must be lengthenedposteriorly and the seat moved back upon them, so as in a measure tooverhang the springs behind; but when this is done it causes the weightof the person or persons occupying the seat to come mainly upon thesprings just at thepoint Where the spring-bars at the rearcome incontact with the springs. This unequal distribution of the weight uponthe. springs causes an unequal action, for the back parts of the springsyield greatly and constantly, while the forward portions thereof yieldvery little.

This causes what maybe termed a rolling motion of the seat. The backpartthereof describes an arc of a circle which has its center somewherein the ellipse formed by the springs. This motion is as unpleasant asthe horse motion and is hardly distinguishable therefrom. To obviatethis I arrange and construct the spring-bars so that when they areplaced upon the springs they come in contact with them rearwardly onlyas far back as the center of the springthat is to say, they are placedupon the spring forward of a line drawn perpendicularly through themiddle portion of said spring. This is shown in Fig. By this arrangementthe weight must of necessity come upon the centerof the spring, and thedescent of the same is practically vertical. When this is done, however,nearlyall of the weight comes upon that point of the spring which hasbeen weakened by having therein the hole for the bolt which holds theleaves of the springs together, and in practical use I have found thatthe spring kept constantly breaking at this point. In order to obviatethis, I provide a plate of iron II, made just as wide as the spring andhaving its extremities made each in the form of a T, as 72, said platebeing provided throughout with suitable holes orperforations forthepassage of the bolts for securing the plates upon the spring, the. Theplate II will preferably be equal in length to that part of thespring-bar which comes in immediate contact with the spring. Itshould beso placed as to reach backward as far as that part of the spring-barwhich is in contact with the spring reaches forward.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a road-cart or other vehicle, the combination, with the thills andthe body, of springs connecting the thills with the body, said springsbeing supported by means of clips secu red beneath the cross-bar, andstraps attached to the forward end of the body and the cross-bar.

2. In a road-cart, the combination,with the thills or shafts, thecross-bar having clips, and the cart-body, of the springs held withinsaid clips, pivotally connected to the cart-body and also connected tothe thills, substantially as described.

3. In a road-cart, the combination of the cart-body and the thills, thesprings consisting of longitudinalcoils, the clips surrounding saidsprings and connected to the crossbar for the purpose of supporting thesprings, the irons for connecting the ends of the springs to the thills,and the irons for 0011- necting the opposite ends of the springs to thebody, substantially as described.

at. The combination, with the thills and the cart-body, of theintermediate springs supported by the cross-bar, said springs having thewire of which they are composed formed at each end with loops or eyes,the irons on the thills bolted to the eyes on one end of the springs,and the irons secured to the body and pivotally connected to the otherends of the springs.

5. In a road-cart, the combination of the TOO thills, the cart-body, thecoiled springs 0on nected at one end to the thills and atthe i the otherend to the thiils and having both :1- ili'Oi'tlhitllli direct motion,and the adjustubie strnps fastened to the eart-body at its forward endand also to the crossbar.

In testimony whereof I zti'fiX my signzttu re in In presence of twowitnesses.

SAMUEL l3. I'INVIN.

other end to the em't-hody,sztid springs being supported by theCl'OSS-bfll',tl1(1' the straps secured at one end to the forward part ofthe body and at the other end to the cross-bar, 5 substantially asdescribed.

6. In a road-cart, the combination of the thills, the cart-body, theCIOSSbZli having clips, the springs supported by said eiips, saidsprings being pivotally connected at one end is to the cart-body andadjustnhiy connected at Witnesses:

(I. A. BEAlTIE, J. M. WALSH.

